Continuous press for pressing gluecoated consolidatable press charges

ABSTRACT

A continuous press for pressing stacked glue-coated laminate and other consolidatable press charges comprises a pair of elongated, vertically-spaced press beds. A pair of vertically-spaced, endless, press belts is positioned between the beds in substantial alignment. A pair of vertically-spaced, endless, anti-friction belts is interposed between the press beds and the press belts in working contact therewith. A suitable drive is connected to the press belts for advancing them in the feed direction at a rate predetermined to effect desired consolidation of the press charge during setting. clamping pressure is applied to the press belts at predetermined intervals along their length to determine the final thickness of the consolidated product.

- March 27, 1973 A. L. TROUTNER 3,723,230

' CONTINUOUS PRESS FOR PRES-SING GLUE-COATED CONSOLIDATABLE, PRESS CHARGES Filed Oct. 12, 1970 s Sheets-Sheet 86 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Q Q '0 O O 0 ARTHUR L. TROUTNER INVENTOR.

BY i

March 27, 1973 TROUTNER 3,723,230

CONTINUOUS PRESS FOR PRESSING GLUE-COATED CONSOLIDATABLE, PRESS CHARGES Filed Oct. 12, 1970 6 Sheets-Sheet 2 O O O ARTHUR L. TROUTNER INVENTOR.

ATTY.

Much 27, 1973 A. L. TROUTNER CONTINUOUS PRESS FOR PRESSING GLUE-COATED CONSOLIDATABLE, PRESS CHARGES 6 Sheets-Sheet 5 Filed Oct. 12, 1970 ARTHUR L. TROUTN ER INVENTOR.

BY ATTY Mmh 27, 1973 CONTINUOUS 'ss Filed Oct. 12, 1970 715p FIG. 5

FIG. I I0 L. OUTNER PRESS GLUE-COATED CONSOLIDATABLE, PRESS ARGES FIG. 9

6 Sheets-Sheet 5 ARTHUR L. TROUTNER INVENTOR BY a W ATTY.

March 27, 1973 A. TROUTNER 3,723,230

CONTINUOUS PRESS FUR IRESSING GLUE-COATED CONSOLIDATABLE, PRESS CHARGES Flled Oct 12 1970 6 Sheets-Sheet 6 ARTHUR L. TROUTNER INVENTOR BY fa 7 ATTY.

United States Patent 3,723,230 CONTINUOUS PRESS FOR PRESSING GLUE- COATED CONSOLIDATABLE, PRESS CHARGES Arthur L. Troutner, Boise, Idaho, assignor to True Joist Corporation, Boise, Idaho Filed Get. 12, 1970, Ser. No. 79,839 Int. Cl. B3011 13/00, 3/00 U.S. Cl. 156-580 ABSTRACT OF THE DISCLOSURE A continuous press for pressing stacked glue-coated laminae and other consolidatable press charges comprises a pair of elongated, vertically-spaced press beds. A pair of vertically-spaced, endless, press belts is positioned between the beds in substantial alignment. A pair of vertically-spaced, endless, anti-friction belts is interposed between the press beds and the press belts in working contact therewith. A suitable drive is connected to the press belts for advancing them in the feed direction at a rate predetermined to effect desired consolidation of the press charge during setting. Clamping pressure is applied to the press belts at predetermined intervals along their length to determine the final thickness of the consolidated product.

17 Claims BACKGROUND OF THE INVENTION This invention relates to a continuous press for pressing glue-coated, consolidatable, press charges into a continuous consolidated product. It pertains particularly to a continuous press for gluing stacked, glue-coated, wood laminae into lumber or plywood and is described with particular reference to this application, although no limitation thereby is intended. The invention relates further to a method for continuously pressing consolidatable press charges.

Over the years occasional attempts have been made to design endless belt type continuous presses for the manufacture of plywood, lumber, and other glued and pressed products. These attempts uniformly have been unsuccessful for various reasons. The character of the press charges has demanded the application of massive equipment having dimensions and weight such'as to make it inoperable, or at least commercially unfeasible. The nature of the press charge has demanded construction of a continuous press of such great length that guiding the charge linearly through the press in proper working relation to the parts thereof has been difficult.

The application of uniform pressure to the charge along the length of the continuous press has presented a serious problem, as has the application of optimum temperature for setting the adhesives and/or plasticizing the charge. Proper feeding of the press charge to the throat of the press has been difficult on a continuous commercial scale.

Precise control of the timing of the drive has presented serious problems, as has proper maintenance and repair of the various machine components. The cost of construction, installation, maintenance and operation often has been prohibitive.

It is the general purpose of the present invention to overcome the foregoing problems by providing a continuous press for glue-coated, consolidatable press charges such as stacked wood laminae, which press is widely applicable to the production of a variety of pressed products, which is comparatively light in weight, which is subject to precise control of all operating variables, which is of relatively simple and practical mechanical design, which is capable of operation at a high production rate, and which is of moderate cost for initial installation and maintenance during its service life.

In the drawings:

'ice

FIGS. 1a and lb are fragmentary views in side elevation of the downstream and upstream ends respectively of the herein described continuous press;

FIG. 2 is a transverse sectional view taken along line 2-2 of FIG. 1b;

FIG. 3 is a fragmentary plan view of the press bed;

FIG. 4 is a fragmentary, detail, plan view of an endless anti'friction belt which is a component of the herein described continuous press, looking in the direction of the arrows 4--4 of FIG. 2;

FIG. 5 is a detail view in elevation of a dimensionlimiting clamp applied to the press, looking in the direction of the arrows of line 5-5 of FIG. lb;

FIG. 6 is a fragmentary view in side elevation of the infeed end of the continuous press, illustrating the manner of heating the press;

F11. 7 is an exploded, perspective view of a ratchet element included in the drive for the press;

FIG. -8 is a longitudinal section, taken along line 88 of FIG. 9; and further illustrating the ratchet drive;

FIG. 9 is a plan view looking in the direction of the arrows of line 9--9 of FIG. -8 and still further illustrating the ratchet drive;

FIG. 10 is a detail sectional view of the ratchet drive taken along line 10-10 of FIG. 8;

FIG. 11 is an end elevation of the ratchet drive, looking in the direction of the arrows 11-11 of FIG. '9 and illustrating the manner of application of the drive to the work-conveying elements of the press; and

FIG. 12 is a detail, transverse, sectional view of the ratchet drive taken along line 12--12 of FIG. 8.

In its broad aspect, the herein described continuous press for pressing stacked, glue-coated, wood laminae and other consolidatable glue-coated press charges in cludes a pair of elongated vertically spaced press beds. A pair of vertically spaced endless belts are positioned between the press beds. A pair of vertically spaced endless anti-friction belts are interposed between the press beds and the press belts in working contact therewith.

The working stretches of the press belts are spaced a distance suflicient to exert a predetermined pressure on the consolidatable press charge passing in pressure contact between them. Drive means connected to the press belts advance them in the feed direction at a rate predetermined to efliect a desired consolidation of the press charge during setting of the glue.

Clamps applied to the press belts at predetermined intervals limit the degree of consolidation of the press charge. Where the press charge has been coated with thermosetting glues, heaters elevate the temperature of the charge to a glue-setting level.

The pressing operation preferably is carried out in stages. Thus the press charge first is consolidated in an infeed zone to a preliminary density. Next, it is overconsolidated in a high pressure zone. Finally it is maintained at the desired final density in a glue setting zone. The spacing of the press belts is determined in all zones by the setting of the clamps. The effect thus is that of pressing against stops as the press charge passes through the clamps spaced along the length of the press.

Considering the foregoing in greater detail and with particular reference to the drawings:

THE PRESS CHARGE As has been indicated above, the presently described press may be applied to the consolidation and gluing of a variety of press materials. It may be applied in general to the continuous pressing of consolidatable press charges comprising matrices the components of which are coated or impregnated with glue. Thus it may be applied to the continuous pressing of felts comprising mineral or woody particles coated with glue, in the manufacture of composition boards.

The press is particularly applicable, however, to the pressing of charges comprising stacked, glue-coated wood laminae in the production of lumber, heavy timbers, and plywood. The laminae advantageously may comprise plywood veneers of any of the various commercial thicknesses.

In the preparation of the stacked laminae, the wood veneers or other sheets first are glue coated by any of the conventional techniques, i.e. by spraying, curtain coating, brushing, or roll coating. Sufiicient glue is employed to fill any voids and coat the surfaces. Thermosetting or cold setting glues may be employed. To ecomonize on press length, it is preferred to employ quick setting glues.

The glue-coated laminae are laid up in a stack 20 having a thickness, width, and pattern determined by the dimensions of the press and the end use to which the pressed product is to be put. Thus the laminae may be stacked uniformly throughout the length of the charge to provide a product of uniform density throughout its length. On the other hand, where products of variable density are desired, the laminae may be stacked nonuniformly to provide areas which, after consolidation in the press, are of greater density than the remaining areas of the pressed product.

However compounded, the press charge is fed into the continuous press of the invention which has for its functions continuously pressing the charge, consolidating it to a predetermined thickness and density, and retaining it in its consolidated condition during setting of the glue. The press basically comprises the press beds, the press belts, the anti-friction belts interposed between the press beds and press belts, the clamps, and the drive means applied to the belts for advancing the press charge through the press.

Considering these basic components in the stated order:

THE PRESS BEDS The press beds, including the associated structural frame, have for their primary functions supporting and backing up the press charge as it moves continuously through the press and is subjected to consolidating pressures. Their construction is illustrated particularly in FIGS. 1, 2 and 3.

The complete press has an overall length determined by such factors as the identity of the raw material being pressed, the thickness of the charge, its thermal conductivity, and the speed with which the glue sets. In general, however, a press of substantial length is contemplated, i.e. a length of from 30 to 80 feet. It is a feature of the invention that in spite of its of its great size, the overall weight of the press may be kept at a minimum.

In the case of a hot press of such substantial size, thermal expansion of the press frame occurring during heating and cooling of the press presents a problem. In the present invention, this problem is overcome by mounting the entire press on a pair of parallel tracks 22 which extend in spaced relation the entire length of the press. The press members then are mounted on parallel slides 24 which engage the tracks. This construction accommodates the oneor two-inch change in length which may occur during operation of the press.

The press beds and remaining elements of the press assembly are supported on a plurality of horizontally spaced, vertical supports arranged in pairs on opposite sides of the press. In the illustrated form of the invention, these supports comprise heavy threaded rods 26, the bases of which are received in sockets, mounted on slides 24. The density per lineal foot of press of rods 26 may vary in accordance with the press pressures in various areas. Their density may be greatest, for example, at the infeed end of the press where preliminary consolidation of the press charge occurs.

Rods 26 support various transverse and longitudinal members comprising the press frame. The more essential of such members include a plurality of transverse structural members 28 adjustably supported on nuts 30; transverse, lower I-beams 36 with attached sleeves 38; and transverse upper I-beams 40 with attached sleeves 42.

I-beams 36 and 40 are mounted on rods 26 by means of sleeves 38, 42 which are telescoped over the rods. Spacers 48 are interposed between the sleeves. The position of the I-beams is adjusted by means of nuts 34, 46. This determines a press opening 50 defined by the press bed plates.

The latter elements of the press assembly comprise heavy upper and lower steel plates 52, 56 secured to, and backed up by, the adjacent surfaces of the I-beams. Bed plates 56 at the infeed end are tapered and of heavy construction to resist the great stresses present during the preliminary consolidation of the press charge. Upper and lower plates 56 converge to form a throat which facilitates feeding of the press charge. It also provides a pre-press zone in which the charge is consolidated to a level approaching its final density. It is to be noted particularly that the bed plates are provided with longitudinally extending, parallel keys 54, the purpose of which will appear hereinafter.

As shown particularly in FIG. 6, the entire body of the press is housed in an insulated case 60 in which are mounted a plurality of spaced infrared lamps, or other space heaters 62. The lamps preferably are located near the infeed end of the press and serve to heat the entire press environment as required to plasticize the press charge and initiate the setting of any thermosetting glues which may be present.

THE PRESS BELTS The press belts have for their function advancing the press charge through the press, consolidating the press charge, and restraining the press charge during setting of the glue. Their construction is illustrated particularly in FIGS. 1, 2 and 11.

Mounted on the frame of the press at the infeed end are a pair of heavy shafts 66 rotatably journaled in bearings 68 at their outer ends. On one or both sides, the two shafts are interconnected and synchronized by meshing gears 70. These synchronize the movement of the two shafts. At the outfced end of the press, there are located a pair of companion shaft 72 journaled in bearings 74.

Sprockets 76 are keyed to the ends of upstream shafts 66; sprockets 78 to downstream shafts 72.

Sprockets 76, 78 mount between them endless chain press belt assemblies each of which includes a pair of spaced, parallel endless drive chains 80. These chains may be of conventional construction including a plurality of cross pins interconnected by overlapped side plates.

Selected ones of the inner side plates of chains 80 have laterally projecting pins 82. These are journaled in bearings 84 mounted in the inner surfaces of press plates 86.

As shown particularly in FIG. lb, the press plates comprise flat, rectangular plates which extend transversely of the press beds and which have their longitudinal side edges closely adjacent each other, thus forming a segmented press belt. The plates are rigid and, in combination with the associated backup components, overcome the problems of flexibility and uneven pressure which heretofore have beset endless belt type continuous presses.

The inner faces of press plates 86 are provided with aligned ribs 88 which register with ribs 54 on the press bed above described.

Tensioning means are provided for maintaining drive chain 76 continuously under resilient pressure. The means employed for this purpose are illustrated in FIG. la.

Bearings 74 which journal shafts 72 at the downstream end of the press are provided with slides 90. The slides track on tracks 92 extending longitudinally of the press at its downstream terminal portion. An hydraulically operated tensioning cylinder 94 with associated hydraulic accumulator is bolted to a frame member and coupled to each of bearings 74. Operation of the cylinders and accumulators applies continuous tensioning force to the press belts as required to maintain them taut under all conditions of operation.

Heating means also are present to assist space heaters 62 in applying sufficient heat to the press charge to plasticize it and set the glue. Steam or electric heaters may be employed for this purpose. Conventional Calrod heaters are indicated at 96 in FIG. 2. The heaters may be suitably mounted, as by bolting them to press bedplates 52 which transmit the heated to press plates 86.

THE ANTI-FRICTION PRESS BELTS Suitable means are included in the press assembly for minimizing the friction which otherwise would be present between the moving press belts and the stationary press beds. The means employed for this purpose comprise endless, anti-fraction belts interposed between the press beds and press belts. The construction of the anti-friction belts is illustrated particularly in FIGS. 1, 2 and 4.

At the infeed end of the press, shafts (torque tubes) 66 mount a pair of freely rotatable sprockets 100. At the outfeed end of the press, separate shafts 102 journaled in bearings 104 mount idler sprockets 106.

Two pairs of endless chains 108 are mounted on and mesh with sprockets 100, 106. The chains mount a plurality of transversely arranged, parallel backup rollers 110, the ends of which journal stub shafts 112 extending laterally outwardly from the side plates of chains 108.

The peripheral surfaces of rollers 110 are formed with annular grooves 114. These register with, and receive keys 54 in the bed plates and keys 88 in the press plates. This provides an eflicient running interlocking of these relatively movable parts of the press assembly and etfectively prevents their lateral displacement with respect to each other during operation of the press, thereby overcoming effectively one of the principal deficiencies of the prior art continuous presses: that of guiding the endless belts accurately and durably along the entire length of the press.

As in the case of the endless press belts, the endless anti-friction belts are provided with tensioning means designed to keep them under optimum running tension at all times. The tensioning means employed is similar to that above described and is illustrated in FIG. 1a.

Bearings 104 journaling shafts 102 at the discharge end of the press are provided with guides 118 which slide on longitudinal tracks 120. The case of at least one tensioning hydraulic cylinder 122 is bolted to a frame member. The piston rod of the cylinder mounts as a cross head bearing 104. The cylinders acting in unison thus apply tensioning pressure to all of the chains as required.

Guide means are applied not only to the working stretches of the two endless belts, but also to the idle stretches thereof.

Thus the upper stretch of the upper anti-friction belt is guided by a pair of longitudinally extending angle irons 126 bolted across the tops of I-beams 40. The angle irons are received in annular grooves 114 of rollers 110. These grooves also receive keys 88 of press plates 86 of the upper stretch of the upper press belt, thereby keying together and stabilizing both belts against lateral displacement during their return trip.

The idle lower stretches of the lower belt assemblies are guided in an analogous manner.

Companion guides 127 are mounted across the under surfaces of I-beams 36 longitudinally of the press. The guides enter annular grooves 114 of rollers 110, FIG. 2. Keys 88 of press plates 86 also enter the grooves, keying the two belts together. In addition, the lower surface of the lower press belt is supported by two series of supporting rollers 130 bolted to the upper surfaces of transverse structural members 28.

THE DRIVE A significant reason for the failure of the prior art continuous presses of the class described herein lies in the fact that the greath length of the presses has made mandatory the application of massive drives, e.g. massive chain and sprocket drives. To provide the necessary strength, these drives necessarily have been so heavy and cumbersome as not only to add enormously to the overall weight of the press, but also to render the drives inoperable.

It thus is a primary advantage of the present invention that this problem is overcome by the application of a drive which enables the use of chain and sprocket systems of relatively light weight. This in turn is made possible by applying a plurality of individual drives to the chains at selected locations, rather than applying the total drive to the sprockets which support the chains.

The novel drive assembly is illustrated particularly in FIGS. 7-12 inclusive.

Although such unit drives are rack and pinion drives, segmental gear drives and the like may be employed, it is preferred to employ rack and pinion drives. The unit drives are mounted at strategic locations along the length of the press. In the case of a continuous lumber press having a length of 60 feet, there may be 8 such drives arranged in pairs on opposite sides. The drives may operate in unison for stepwise advancement of the Work, or at staggered intervals to provide continuous advancement of the work.

In the illustrated form of the invention each drive unit is supported demountably on one of support rods 26 by means of a split bracket 134, the two parts of which are bolted together. The bracket supports an air or hydraulic cylinder 136. The piston rod of the cylinder is coupled to a ratchet body indicated generally at 138 and, as shown particularly in FIG. 7, consisting of five telescoping parts.

These include a first angular side piece 140 having an integral back plate 142 provided with a threaded opening 144 by means of which the ratchet body is coupled to the piston rod of cylinder 136. Nesting within this component are a second side piece 146, a pair of guide blocks 148 and an alignment block 150.

Male and female ratchet fingers 152, 154, a springretaining block 156 and a coil spring 160 complete the assembly. Ratchet fingers 152, 154 are provided with openings which register in the assembled condition of the ratchet with an opening through resistor 156, thereby providing a housing for retaining the spring.

The elements of the ratchet are assembled by bolting them together in the manner indicated in FIG. 7 with assembly bolts 161 and shouldered pivot bolt 162. When the ratchet is mounted on the piston rod of cylinder 136 in the operative position of FIGS. 8 and 9, guide blocks 148 enter the spaces between the side plates of upper and lower endless chains 80, thereby guiding the ratchet and chain relative to each other so that both are maintained in operative position. Alignment block 150, cooperating with spring 160, positions the ratchet fingers 152, 154 so that they are resiliently in contact with the cross pins of the chains. It also insures that equal pressure is transmitted to the crosspins of the chains even though they may be somewhat out of vertical alignment. Reciprocation of cylinder 136 thus produces a ratcheting drive of the chain, stepwise, a distance determined by the stroke of the cylinder, and the chain pitch.

THE CLAMP ASSEMBLY As the press charge advances through the press, it is subjected to the action of clamp means which determine precisely the degree of consolidation of the charge as well as the final thickness of the pressed product. The effect is similar to the effect produced by pressing to stops in a platen type press.

The clamp means employed for this purpose is illustrated in FIGS. lb and 5.

Each clamping assembly includes a pair of massive clamp plates 164 arranged vertically and supported on threaded bolts 166 provided with nuts 168. Clamps plates 164 are contoured to bear against the inside faces of press bed plates 52. The spacing between the clamp plates may be precisely adjusted by means of nuts 168 on threaded rods 166.

The clamping assemblies are located at critical intervals along the length of the press. As the press charge is driven between them, it necessarily is consolidated to a thickness determined precisely by the spacing between the clamp plates.

OPERATION The operation of the herein described continuous press is as follows:

A press charge such as stacked, glue-coated wood laminae is introduced into the throat of the press between endless press belts including press plates 86. As the charge progresses from right to left as viewed in FIG. 1, it is subjected first in a prepress zone to a progressively increasing pressure as required to consolidate it to a density approaching its final density. At the same time it is subjected to heat supplied both by space heaters 62, FIG. 6 and Calrod heaters 96, FIG. 2. The heat softens the charge, making it more pliant and thus more readily sus ceptible to consolidation. It also initiates and promotes the setting of thermosetting glues, if such have been employed.

The press charge is advanced through the press by the operation of cylinder-driven ratchet assemblies 138 operated in unison or in staggered sequence, depending upon whether intermittent or continuous progress of the press charge is desired.

As the charge passes through the press, it is restrained by press plates 86 of the press belts backed up by bed plates 52, 56 of the press. Rollers 110 interposed between these two members and mounted on an idling chain sprocket assembly including chains 108 reduce the friction so that smooth progress of the work is achieved.

After leaving the prepress zone the press charge enters an overconsolidation zone having for its function overconsolidation of the charge to a predetermined degree. In this zone, pressures of the order of 500-1000 pounds per square inch may be applied. They are achieved by forcing the press charge between adjustable clamp plates 164, FIG. 5, set to a predetermined spacing and backing up press bed plates 52. One or more of the clamping assemblies may be applied to the press along its length, as required to determine the thickness and density of the final product.

Next the charge enters a restraining zone wherein the pressure is reduced to levels of from 50-200 pounds per square inch, or even lower pressure. The purpOse of passing the charge through this zone is to restrain it within desired thickness limits during setting of the glue. Again the restraint is achieved by the application of clamping assemblies including clamp plates 164. At the conclusion of the pressing operation, the finished consolidated product is discharged from the press after which it may be cut to length by cut-off saws of appropriate design, and transmitted to further processing.

Having thus described my invention in preferred embodiments, I claim:

1. A continuous press for pressing glue-coated, consolidatable, press charges comprising:

(a) a pair of elongated, vertically-spaced press bed means,

(b) a pair of vertically-spaced, endless, press belt means positioned between the press bed means in substantial alignment therewith,

(c) a pair of vertically-spaced, endless, anti-friction belt means interposed between the press bed means and the press belt means in substantial alignment and in working contact therewith,

(d) the working stretches of the press belt means being spaced a distance sulficient to exert a predetermined pressure on a consolidatable press charge passing in pressure contact between them, and

(e) drive means connected to the press belt means for advancing them in the feed direction at a rate predetermined to effect a desired consolidation of the press charge during setting of the glue,

(f) the vertical spacing of the press bed means along its length being adjusted to provide three zones: an inwardly tapered infeed zone wherein the press charge is gradually consolidated; immediately downstream from the infeed zone an overconsolidation zone wherein the work is resiliently consolidated to a level more than that desired in the final product; and immediately downstream from the overconsolidation zone a final zone wherein there is applied to the press charge pressure suflicient to maintain it at the desired degree of consolidation during setting of the glue for the remainder of its travel through the press.

2. A continuous press for pressing glue-coated, consolidable, press charges comprising:

(a) a pair of elongated, vertically-spaced press bed means,

(b) a pair of vertically-spaced, endless, press belt means positioned between the press bed means in substantial alignment therewith,

(c) a pair of vertically-spaced, endless, anti-friction belt means interposed between the press bed means and the press belt means in substantial alignment and in working contact therewith,

(d) the working stretches of the press belt means being spaced a distance sufiicient to exert a predetermined pressure on a consolidatable press charge passing in pressure contact between them,

(c) drive means connected to the press belt means for advancing them in the feed direction at a rate predetermined to effect a desired consolidation of the press charge during setting of the glue, and

(f) support and guide means for supporting and guiding the idle stretches of the press belt means, the press belt support means comprising a plurality of rollers mounted longitudinally of the press beneath and in supporting engagement with the idle lower stretch of the lower press belt means, and a pair of slides mounted longitudinally of the press beneath and in supporting engagement with the idle upper stretch of the upper anti-friction belt means.

3. A continuous press for pressing glue-coated, consolidatable, press charges comprising:

(a) a pair of elongated, vertically-spaced press bed means,

(b) a pair of vertically-spaced, endless, press belt means positioned between the press bed means in substantial alignment therewith,

(c) a pair of vertically-spaced, endless, anti-friction belt means interposed between the press bed means and the press belt means in substantial alignment and in working contact therewith, the anti-friction belt means comprising roller belt means comprising two pairs of sprocket-mounted endless chains arranged longitudinally in back of the working stretches of the press belt means, and a plurality of horizontally spaced rollers rotatably mounted transversely between each pair of chains,

(d) the working stretches of the press belt means being spaced a distance suflicient to exert a predetermined pressure on a consolidatable press charge passing in pressure contact between them, and

(e) drive means connected to the press belt means for advancing them in the feed direction at a rate predetermined to effect a desired consolidation of the press charge during setting of the glue.

4. The press of claim 3 wherein the rollers are provided with at least one annular groove and wherein the press bed means and press belt means with which they are associated are provided with at least one outwardly projecting rib dimensioned to enter the groove on the rollers, thereby providing guide means preventing lateral displacement of the press bed means, press belt means, and roller belt means relative to each other.

5. A continuous press for pressing glue-coated, consolidatable press charges comprising:

(a) a pair of elongated, vertically-spaced press bed means,

(b) a pair of vertically-spaced, endless, press belt means positioned between the press bed means in substantial alignment therewith, the press belt means comprising two pairs of sprocket-mounted endless chains extending longitudinally of the press, one pair above and one below the press charge, a plurality of closely adjacent press plates arranged transversely between the members of each chain pair, and connecting means connecting the plates to the chains,

(c) a pair of vertically-spaced, endless, anti-friction belt means interposed between the press bed means and the press belt means in substantial alignment and in working contact therewith,

(d) the working stretches of the press belt means being spaced a distance sui'ficient to exert a predetermined pressure on a consolidatable press charge passing in pressure contact between them, and

(e) drive means connected to the press belt means for advancing them in the feed direction at a rate predetermined to effect a desired consolidation of the press charge during setting of the glue.

6. The press of claim including longitudinal chain guide means comprising plates extending longitudinally of the press beneath the working stretches of the chains, underlying and guiding the same in contact therewith.

7. A continuous press for pressing glue-coated, consolidatable, press charges comprising:

(a) a pair of elongated, vertically-spaced press bed means,

-(b) a pair of vertically-spaced, endless, press belt means positioned between the press bed means in substantial alignment therewith, each press belt means comprising a pair of sprocket-mounted endless chains with transverse press plates mounted thereon, and the drive means comprises ratchet drive means engaging the chains for driving them in the feed direction,

(c) a pair of vertically-spaced, endless, anti-friction belt means interposed between the press bed means and the press belt means in substantial alignment and in working contact therewith,

(d) the working stretches of the press belt means being spaced a distance sufiicient to exert a predetermined pressure on a consolidatable press charge passing in pressure contact between them, and

(e) drive means connected to the press belt means for advancing them in the feed direction at a rate predetermined to etfect a desired consolidation of the press charge during setting of the glue.

8. The press of claim 7 wherein the ratchet drive means comprise a plurality of fluid-operated cylinders each including a reciprocating piston mounting a ratchet arranged to engage the chain.

9. The press of claim 7 wherein the ratchet drive means comprises a plurality of fluid-operated cylinders each including a reciprocating piston mounting a ratchet arranged to engage the chain and a fluid circuit supplying fluid to the pistons and energizing them in unison with each other to provide stepwise advancement of the press belt means.

10. The press of claim 7 wherein the ratchet drive means comprise a plurality of fluid-operated cylinders each including a reciprocating piston mounting a ratchet arranged to engage the chain, and a fluid circuit supplying the fluid to the pistons and engaging them in alternate relation to each other to provide continuous advancement of the press belt means.

11. The press of claim 7 wherein each ratchet comprises a case, means for connecting the case to the piston rod of the cylinder, a transverse shaft in the case, a pair of ratchet fingers pivotally mounted on the shaft, and

5 resilient means interconnecting the fingers for urging them normally toward an angnlarly extended position.

12. The press of claim 11 wherein the resilient means comprise compression spring means and a retainer positioned between the fingers for retaining the spring means.

'13. The press of claim 11 including stop means mounted on the shaft and positioned for arresting the extending angular movement of the fingers at a predetermined angular limit.

14. A continuous press for pressing glue-coated, con- 15 solidatable, press charges comprising:

(a) a pair of elongated, vertically-spaced press bed means,

(b) a pair of vertically-spaced, endless, press belt means positioned between the press bed means in substantial alignment therewith,

(c) a pair of vertically-spaced, endless, anti-friction belt means interposed between the press bed means and the press belt means in substantial alignment and in working contact therewith,

pressure contact between them,

(e) drive means connected to the press belt means for advancing them in the feed direction at a rate predetermined to effect a desired consolidation of the press charge during setting of the glue, and

(f) tensioning means applied to the endless press belt means and the endless anti-friction belt means for maintaining the same resiliently under tension.

15. The press of claim 14 wherein the tensioning means comprise fluid operated tensioning cylinder means.

16. In a continuous press or like apparatus including a chaln and sprocket drive having a chain comprising a plurahty of side plates interconnected by cross pins, a ratchet drive comprising:

(a) a ratchet body,

(b) a guide plate arranged longitudinally of the body and dimensioned for entering the space between the 17. In a continuous press including a pair of resilient press beds arranged in spaced relation on both sides of a press charge and means for driving a press charge be tween the beds, clamp means comprising:

of the press beds in contact therewith, and

(b) screw means interconnecting the clamp plates for adjusting the spacing between them, thereby determining the thickness and degree of consolidation of the press charge passing between the press beds.

References Cited UNITED STATES PATENTS Re. 21,723 Re. 22,200 554,847 1,806,006 3,366,0 70 37 EDWARD G. WHITBY, Primary Examiner US. Cl. X.R.

(d) the working stretches of the press belt means being spaced a distance sufficient to exert a predetermined pressure on a consolidatable press charge passing in (a) a pair of clamp plates positioned one on each side Thompson 100-152 X Richardson 100-152 X Walters et al 100-4152 Upson et a1. 100-118 X Drake 100-93 P 

